CVE-2026-25819Network attack vector

Unauthenticated reboot via crafted HTTP request

Published Mar 12, 2026 · Updated Mar 12, 2026

Denial of service in Ewon Flexy, Cosy 131, and Cosy+ firmware allows remote attackers to reboot gateways with a crafted HTTP request. Affected releases are Flexy and Cosy 131 before 15.0s4, Cosy+ 22.xx before 22.1s6, and Cosy+ 23.0s0 through 23.0s2; HMS has not disclosed which GUI endpoint or request element mishandles the crafted input. Exploitation requires unauthenticated network access to the device GUI; firmware 15.0 and later blocks WAN GUI access by default, and the reported consequence is a reboot.

CVSS severity8.7
High
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Ewon Flexy, Cosy 131, and Cosy+ firmware allows remote attackers to reboot gateways with a crafted HTTP request. Affected releases are Flexy and Cosy 131 before 15.0s4, Cosy+ 22.xx before 22.1s6, and Cosy+ 23.0s0 through 23.0s2; HMS has not disclosed which GUI endpoint or request element mishandles the crafted input. Exploitation requires unauthenticated network access to the device GUI; firmware 15.0 and later blocks WAN GUI access by default, and the reported consequence is a reboot.

The record

CVE
CVE-2026-25819
Published
Mar 12, 2026
Updated
Mar 12, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.7HMS NetworksCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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